Schwannomas are uncommon benign neoplasms arising from the Schwann cells lining the nerve sheath. Retroperitoneal schwannomas are extremely rare constituting about 0.3‐3.2% of all retroperitoneal masses. Pancreatic schwannomas are obsolete and less than 50 cases reported until date in the literature. Ancient schwannomas is a histological variety in which there would be degenerative changes occu...

Ancient schwannomas are benign long standing schwannomas of the neural sheaths. Histological findings are these seen as in conventional schwannomas, but ancient schwannomas additionally demonstrate cystic hemorrhagic changes and degenerative nuclei with pleomorphism and hyperchromasia. Due to the nuclear atypia, and cystic degeneration, ancient schwannomas might be confused with malignant tumor...

Schwannomas are benign tumors originating from Schwann cells, which the main component of neural sheath. Biliary schwannomas extremely rare. We report case a 78-year-old man who presented with no abdominal symptoms or jaundice. CT imaging showed hyperdense mass extending along extrahepatic bile duct, and upstream ducts were dilated. performed duct resection under preoperative diagnosis cancer. ...

Sporadic and neurofibromatosis type 2-associated schwannomas contain a glial growth factor (GGF)-like activity that has been hypothesized to promote neoplastic Schwann cell mitogenesis. It is not known whether this GGF-like activity is neuregulin-1 (NRG-1), an epidermal growth factor (EGF)-related molecule that regulates the proliferation, survival, and differentiation of developing Schwann cel...

BACKGROUND AND METHODS 44 peripheral nerve sheath tumors (PNST) (27 schwannomas, 9 neurofibromas and 8 malignant peripheral nerve sheath tumors (MPNST)) were analyzed to determine DNA ploidy pattern and to clarify the conflicting data in the literature concerning this topic (whether benign PNSTs are aneuploid or not). For further insight we analyzed 6 schwannomas, one atypical neurofibroma and ...

BACKGROUND AND PURPOSE Benign tumors of the internal auditory canal (IAC) may leave the confines of the IAC fundus and extend into inner ear structures, forming a dumbbell-shaped lesion. It is important to differentiate dumbbell lesions, which include facial and vestibulocochlear schwannomas, from simple intracanalicular schwannomas, as surgical techniques and prognostic implications are affect...

TARGET POPULATION Adults diagnosed with vestibular schwannomas. QUESTION 1 What is the prognostic significance of Antoni A vs B histologic patterns in vestibular schwannomas? RECOMMENDATION No recommendations can be made due to a lack of adequate data. QUESTION 2 What is the prognostic significance of mitotic figures seen in vestibular schwannoma specimens? RECOMMENDATION No recommendat...

Reprint requests to: Dr. Yu-Chang Lee Department of Radiology E-Da Hospital/I-Shou University. No.1, Yi Da Road, Jiau-shu Tsuen, Yan-Chau, Kaohsiung 824, Taiwan, R.O.C. Schwannomas are common neoplasms in the head and neck region, but of these tumors only less than 4% was found in sinonasal location in the reported literature. Most of the reported cases are found in the maxillary or ethmoid sin...

Schwannomas are neurogenic tumors arising from the Schwann cells present in neural sheath of myelinated nerves. These benign that can arise anywhere body. rarely seen nose and paranasal sinuses representing <4% all head-and-neck schwannomas. Surgical excision is treatment choice these cases. Nasal polyps common nasal cavity lesions which usually inflammatory polyps. Schwannoma presented with...